论文推荐|西安科技大学赵庆志教授：GNSS与FY-4A辅助WRF-Hydro耦合模型的稀缺区径流新预报方法

Numerous small and medium-sized basins have complex terrain and lack basic hydro-meteorological data, significantly hindering the advancement of hydrological forecasting methods. One of the effective strategies to address the scarcity of data and the short forecast period in small and medium-sized basins involves using meteorological data from the Numerical Weather Prediction (NWP) model to drive the hydrological model. This approach is a central focus of this study. A novel streamflow forecasting method of Weather Research and Forecasting (WRF)/WRF-Hydro one-way coupling system assisted by the Global Navigation Satellite System (GNSS) and Fengyun-4A (FY-4A) satellite is proposed. The external precipitable water vapor (PWV) is introduced into the WRF model for three-dimensional variational (3Dvar) assimilation to forecast meteorological data, and combined with high-resolution and high-precision precipitation to provide meteorological forcing data for the WRF-Hydro model. Fourteen typical flood events in the Yuehe catchment from 2020 to 2023 are selected, and three forcing scenarios are designed to drive the WRF-Hydro model. Results show that the accuracy of the WRF model forecasted precipitation is improved by assimilating GNSS PWV and FY PWV. The mean root mean square error (RMSE) is less than 2 mm/h, and the mean correlation coefficient (R) is increased by 8 % with all stations passing the 95 % confidence level. In terms of streamflow forecasting, the proposed method can effectively improve the simulation effect on spatial runoff generation and confluence process in the Yuehe catchment and accurately capture the occurrence time of flood peak. During the verification period, the mean Nash efficiency coefficient (NSE) and coefficient of determination (R2) of floods are 0.53 and 0.72, respectively. Meanwhile, the mean absolute value of the relative error of the flood volume (Dp) and the error of the flood peak time (DT) are 11 % and 2.0 h, respectively. Such results prove that the proposed WRF/WRF-Hydro one-way coupling system driven by high-resolution precipitation shows good hydrological utility in the Yuehe catchment, which can be further effectively applied in small and medium-scale mountain basins with scare data.